1. Field of the Invention
This invention relates to an apparatus and method for applying a tubular member over a container, and is particularly adaptable for use in applying heat shrinkable seals to container tops so as to render the containers tamper resistant.
2. The Prior Art
In many industries, particularly the pharmaceutical industry, it is desirable to provide for the cap sealing of product containers for reasons of safety, tamper-proofing, sanitation, etc. Several known apparatus exist for effecting such desired cap sealing. Typically, such apparatus include a supply of flattened tubular heat shrinkable members, a pick-up mechanism, means for opening the tubular members, means for delivering the opened tubular members to an application station, means for applying the opened tubular members to containers as they are conveyed past the application station, and means for heating the tubular members so that they shrink around and conform to the shape of the containers thus sealing the containers. The tubular material is generally supplied to the apparatus by loading pre-cut individual members into a hopper or by employing a continuous web of flattened tubular material that is cut into individual members.
Unfortunately, however, there are shortcomings associated with such apparatus. For example, known apparatus generally employ a pick-up mechanism that relies on vacuum means, such as vacuum cups or the like, to pick up the tubular members from the supply source. Such reliance on a vacuum pick-up generally limits the speed at which the pick-up mechanism can operate, there being required a sufficient time delay for an adequate vacuum to be generated so as to enable the vacuum means to fully suck and firmly hold the tubular members from the supply source. As a result, many known apparatus must operate at an undesirable slow speed or with a stop-start intermittent motion.
Another shortcoming associated with known apparatus is that they tend to be quite complicated in structure, thus undesirably raising the cost of manufacturing and maintaining such apparatus. For example, several known apparatus employ multiple turrets for picking up the tubular members and delivering them to the application station, along with complicated mechanisms for effecting the opening of the tubular members and the pushing down of the tubular members onto the containers to be sealed.
A further shortcoming associated with known apparatus, particularly those employing a supply roll of tubular material, is that such apparatus, at times, cut and apply inconsistently dimensioned tubular members to containers. This can cause ineffective cap sealing when, for example, the tubular members are cut too short, or difficulty in opening the containers when the tubular members are cut too long. It also gives the sealed containers an unsightly appearance. Such inconsistencies may be attributable to the fact that the drive means, e.g. the motor, that effects the feed of the tubular web to the apparatus cutter generally also effects the drawing of the web from the supply roll. It will be appreciated that a motor powerful enough to draw a web from a fully loaded supply roll cannot be as sensitive as desired for feeding a precise length of material for cutting.
Still another shortcoming associated with known apparatus is that they often fail to sufficiently open the tubular members resulting in the misapplication of the members to the container.
It is an object of this invention to provide an apparatus and method for applying tubular members to containers that employs a pick-up mechanism that mechanically grips the tubular members from the supply source, opens the tubular members, and delivers the tubular members to an application station, in a continuous, high-speed, non-stop manner.
It is another object of this invention to provide an apparatus and method as above that insures the accurate application of consistently dimensioned tubular members to containers.
It is a further object of this invention to provide an apparatus as above that is simple in construction.